parent = dentry->d_parent;
spin_lock(&parent->d_lock);
spin_lock_nested(&dentry->d_lock, DENTRY_D_LOCK_NESTED);
- list_del_init(&dentry->d_u.d_child);
+ list_del_init(&dentry->d_child);
spin_unlock(&dentry->d_lock);
spin_unlock(&parent->d_lock);
remove_dir(dentry);
return retval;
}
+static int cgroup_allow_attach(struct cgroup *cgrp, struct cgroup_taskset *tset)
+{
+ struct cgroup_subsys *ss;
+ int ret;
+
+ for_each_subsys(cgrp->root, ss) {
+ if (ss->allow_attach) {
+ ret = ss->allow_attach(cgrp, tset);
+ if (ret)
+ return ret;
+ } else {
+ return -EACCES;
+ }
+ }
+
+ return 0;
+}
+
+int subsys_cgroup_allow_attach(struct cgroup *cgrp, struct cgroup_taskset *tset)
+{
+ const struct cred *cred = current_cred(), *tcred;
+ struct task_struct *task;
+
+ if (capable(CAP_SYS_NICE))
+ return 0;
+
+ cgroup_taskset_for_each(task, cgrp, tset) {
+ tcred = __task_cred(task);
+
+ if (current != task && cred->euid != tcred->uid &&
+ cred->euid != tcred->suid)
+ return -EACCES;
+ }
+
+ return 0;
+}
+
/*
* Find the task_struct of the task to attach by vpid and pass it along to the
* function to attach either it or all tasks in its threadgroup. Will lock
if (!uid_eq(cred->euid, GLOBAL_ROOT_UID) &&
!uid_eq(cred->euid, tcred->uid) &&
!uid_eq(cred->euid, tcred->suid)) {
- rcu_read_unlock();
- ret = -EACCES;
- goto out_unlock_cgroup;
+ /*
+ * if the default permission check fails, give each
+ * cgroup a chance to extend the permission check
+ */
+ struct cgroup_taskset tset = { };
+ tset.single.task = tsk;
+ tset.single.cgrp = cgrp;
+ ret = cgroup_allow_attach(cgrp, &tset);
+ if (ret) {
+ rcu_read_unlock();
+ goto out_unlock_cgroup;
+ }
}
} else
tsk = current;